This project has continued the previous study of maternal behavior and infant development in rhesus and pigtail macaques and investigated the occurrence of maternal abuse and neglect of offspring in macaques and mangabeys. The analysis of demographic, reproductive, and clinical data concerning several families of pigtail macaques (> 300 individuals) and mangabeys (>500 individuals) over a period of 35 years has provided the first evidence of intergenerational transmission of infant abuse in primates. The behavioral comparison of 10 abusive and 10 control rhesus mothers has provided the first evidence that infant abuse is associated with highly controlling parenting styles. The study of normal and abnormal maternal behavior in group-living monkeys has highlighted some important parallels between primate and human parenting and improved our understanding of some general principles regulating the mother-child relationship.